MySQL Unreliable

[Marc Perkel <ma...@perkel.com>]

Need a little help for MySQL users.

I'm running several servers that are using a common MySQL server for 
bayes for all the SA servers. What I'm seeing is that MySQL is just 
plain unreliable. The database is often corrupted and it does so in a 
manner that basically causes SA to hang until it times out. I'm not sure 
what I'm doing wrong or if there's some my.cnf settings I'm missing. I 
could use some tips from those of you who are hitting MySQL hard or 
might suggest something other than MySQL that I should use for bayes.

Thanks in advance.

Re: MySQL Unreliable

[SM <sm...@resistor.net>]

Hi Mark,
At 09:15 16-05-2008, Marc Perkel wrote:
>OK - I'm trying that. So innodb is better?

InnoDB supports transactions.  The entire table is not locked as with 
MyISAM when data is inserted, updated or deleted.  That's better in 
the case of a Bayes database.  In general, there is a performance hit 
when using InnoDB.  You should however see better performance for Bayes.

In your original message, you mentioned that the db was being 
corrupted.  That shouldn't happen unless there was an incorrect 
shutdown of the MySQL server.  The hang you mentioned might be a 
query waiting on a lock.

Regards,
-sm 

Re: MySQL Unreliable

[Marc Perkel <ma...@perkel.com>]

SM wrote:
> At 06:30 16-05-2008, Marc Perkel wrote:
>> I'm running several servers that are using a common MySQL server for 
>> bayes for all the SA servers. What I'm seeing is that MySQL is just 
>> plain unreliable. The database is often corrupted and it does so in a 
>> manner that basically causes SA to hang until it times out.
>
> Don't use MyISAM.
>
> http://dev.mysql.com/doc/mysql/en/innodb.html
>
>

OK - I'm trying that. So innodb is better?

Re: MySQL Unreliable

[SM <sm...@resistor.net>]

At 06:30 16-05-2008, Marc Perkel wrote:
>I'm running several servers that are using a common MySQL server for 
>bayes for all the SA servers. What I'm seeing is that MySQL is just 
>plain unreliable. The database is often corrupted and it does so in 
>a manner that basically causes SA to hang until it times out.

Don't use MyISAM.

http://dev.mysql.com/doc/mysql/en/innodb.html

Regards,
-sm 

Re: MySQL Unreliable

[Steven Stern <su...@sterndata.com>]

Marc Perkel wrote:
> Need a little help for MySQL users.
> 
> I'm running several servers that are using a common MySQL server for 
> bayes for all the SA servers. What I'm seeing is that MySQL is just 
> plain unreliable. The database is often corrupted and it does so in a 
> manner that basically causes SA to hang until it times out. I'm not sure 
> what I'm doing wrong or if there's some my.cnf settings I'm missing. I 
> could use some tips from those of you who are hitting MySQL hard or 
> might suggest something other than MySQL that I should use for bayes.
> 
> Thanks in advance.
> 

We use innodb for all the sa_bayes tables.  Here's some tuning settings 
we use in  my.cnf for the server:

query_cache_limit = 1M
query_cache_size = 12M
query_cache_type = 1
innodb_additional_mem_pool_size=12M
innodb_buffer_pool_size=70M
innodb_log_file_size=10M